Thin spring locks and unlocking means therefor



June 2, 1970 HERBERT'LUDWIG WIESMANN THIN SPRING LOCKS AND UNLOCKINGMEANS THEREFOR Filed Dec. 18, 1967 3 SheetsSheet 1 11/21/11,: 'I/IIIIII.

ATTORNEY lNVENTOR HERBERT LUDWIG WIESMANN June 1970 HERBERT-LUDWIGWIESMANN 3,514,979

THIN SPRING LOCKS AND UNLOCKING MEANS THEREFOR Filed Dec. 18, 1967 3Sheets-Sheet 8 FIG. 4

FIG.5

INVENTOR HERBERT LUDWIG WIESMANN ATTORNEY HERBERT-LUDWIG WIESMANN 3,51

June 2, 1970 THIN SPRING LOCKS AND UNLOCKING MEANS THEREFOR Filed Dec.18, 1957 3 Sheets-Sheet 3 FIG.6

ATTORN EY United States Patent 0,

Int. Cl. Eb 65744; E05c 1/12 US. CI. 70-81 9 Claims ABSTRACT OF THEDISCLOSURE A flat, thin spring lock for use in narrow confined Spaces,as in a thin cabinet door or similar closure, particularly adapted forairplanes or other vehicles where protruding handles or knobs areundesirable. The lock and door are operated by a bell crank leverpivoted on the lock casing having one lever arm within the lock casingand attached to the latch actuating mechanism, and the other lever armoutside and overlying the casing and adjacent thereto so that it doesnot protrude when the door is locked. To unlock, the outside lever armis moved first by a finger to an unlocking position where it isangularly related to the door and thereafter it may be grasped byseveral fingers, to exert a dooropening force thereon. In anotherembodiment, the lever arm is biased by a spring in an unlockingdirection but is prevented from moving therein by a trip means. A pushbutton disables the trip means whereby the spring moves the lever arminto its projected position where it may be used as the door handle.

This invention relates to spring locks, particularly of the flat thintype.

In certain eviron-ments, such as in airplanes, land vehicles and similarlocations, locks for doors, windows and similar closures or for drawersand the like must be of special dimensional design to fit within thenarrow confines of a closure or wall space. For safety reasons, no partsof the lock, such as handles or knobs, may protrude from or above thelock casing closure or the wall, that is, the entire lock unit should beflush with the surface of the closure or wall. The lock should alsoeffectively maintain the closure in its locked position against allforces tending to disturb it, such as, for example, centrifugal forcesin airplanes, but still be so constructed as to be easily operated toits unlocked position.

An object of this invention is to provide a lock having all its elementswithin a flat, thin casing so that it fits within the available limitedspace provided by the closure or wall structure of the cabinet orvehicle.

Another object is to provide a lock with a latch biased by asufliciently strong spring to retain it in its locked position againstall undesired forces tending to move it in the opposite direction.

Another object is to provide a lock with a spring urged latch and ahandle to move it against the spring, the handle, when in the normalinoperative position, lying flush against the lock casing. The handle isprovided with an accessible grip portion whereby it can be gripped by afinger and moved to overcome the latch spring and to withdraw the latch.In the final position, the handle may be grabbed by several fingers andused as a pull to open the door, drawer, or any movable device to whichthe lock is attached.

A further object is to provide a trans-mission means between the handleand the latch whereby the latch can bemoved easily and quickly with noundue force exerted by the finger of the operator.

3,514,979 Patented June 2, 1970 Another object is to provide a lock asdescribed above wherein the handle is spring operated and controlled bya push button.

A further object is to provide a locking device to prevent latchwithdrawing movement and thereby effectively lock the closure.

Other objects and advantages of this invention will become apparent uponconsideration of the following specification and the attached drawingwherein:

FIG. 1 shows a top view of a spring lock according to the invention;

FIG. 2 shows a section according to line II-'II in FIG. 1;

FIG. 3 shows a section according to line l-IIIII in FIG. 1;

FIG. 4 shows a top view of a different embodiment of the spring lock;

FIG. 5 shows a section according to line VV in FIG. 4;

FIG. 6 shows a further modification in which the spring lock is openedby means of a push button; and

FIGS. 7 and 8 show in two views and on an enlarged scale the safetydevice shown in FIG. 1.

FIGS. 1 to 3 show a lock housing which consists of a lock box 1 and acover plate 2 which is fastened thereto by means of screws 3 threadedinto sockets 5 of the lock welded to bottom 4 of the lock box. The sidewalls of the lock box 1 have bent extensions 6 to which threaded sockets7 are welded. The lock casing may be fastened to the desired structureby means of screws threaded into sockets 7. In the disclosed embodiment,numeral 8 designates the rear wall of a door panel to which the lock issecured. The front wall 9 of the door panel is cut out and overlapssomewhat the ends of the bent extensions 6 which are once more bent atan angle. The lock box 1, furthermore, is formed in one piece with acuff 10 in which an opening has been provided for the passage andguidance of the catch or latch 11 of the lock.

Latch 11 is biased by a relatively strong spring 12 to its outwardposition and is guided in its slidable motion by formations 13, 14 and15 struck from or otherwise formed in the lock box. Latch 11 comprisesan elongated members having the usual bevel or cam surface at its frontor outward end to cooperate with a keeper element (not shown), andhaving an inward end 16 in the form of a toothed rack which meshes witha gear segment 17 journaled around a pivot 18 suitably secured withinthe lock box. As shown, pivot 18 may be in the form of a rivet. Anelement 19, which may be a struck-up portion, of gear segment 17, or aseparate element secured to the gear segment, is located on gear segment'17 on the side of pivot 18 remote from the gear teeth of segment 17.Thus, as shown in FIG. 1, a force applied to element 19 to move it tothe right causes clockwise movement of gear segment 17 around pivot 18with the resulting withdrawal movement of latch 11 to the left againstthe bias of spring 12.

The withdrawal movement of gear segment means 17, 19 is accomplished bymeans of a bell crank lever 20 which pivots on a shaft 21 supported inthe side walls of lock box 1. Bell crank lever 20 has a short arm 22directed toward the inside of the lock adjacent element 19, and a longerlever arm 23 which normally lies flat on the cover plate 2 andterminates over a portion of recess 24 provided approximately in themiddle in the cover plate 2. Lever arm 23, lying on the outside, isabout the width of the lock and covers up the heads of the screws 3.

To open the closure or device to which the lock is secured, a finger isplaced within recess 24 below lever arm 23 and lever arm 23 is movedupwardly. As bell crank pivots around shaft 21, its other end 22 engageselement 19 on gear segment 17 and moves it to the right, as viewed inFIGS. 1 and 2. As explained above, such movement causes gear segment 17to move clockwise and thereby move rack portion 16 and latch 11 to theleft to release it from its keeper. In the fully withdrawn position oflatch 11, lever arm 23 of hell crank 20 is in a position generallyperpendicular, or angularly related, to the closure and therefore it canbe grasped by other fingers and utilized as a pull handle to pull theclosure to open position. Thus, bell crank lever acts as a latchwithdrawing or unlocking means and. thereafter as a closure pull handle.

Upon release of lever arm 23, spring 12 forces latch 11 and therebytransmission means 16, 17, 19 and bell crank 20 to their normal position(FIG. 1). If the closure is not fully closed, any vibration of thesupport mounting the lock will cause bell crank 20 to audibly rattlearound its shaft 21 and thereby call attention to the fact that latch 11is not fully engaged by its keeper, that is, the

closure is not completely locked.

In the embodiment shown in FIGS. 4-5, spring 12 is eliminated, andthereby the overall length of the lock casing is reduced. As shown inFIG. 4, a tension spring 12a is secured to a socket 3a and to gearsegment 17a, whereby spring 12a biases latch 11 to its locked position.Gear segment 17a is provided with a plurality of holes or bores 25.Element 19a is in the form of a pin, and by placing it in a selectedbore 25, the radial distance between pin 12a and pivot 18 may be varied,and thereby the throw or withdrawal movement of latch 11 may be varied.The location of the line on which the centers of bores are located isdefined by a line passing through pivot 18 and through the point ofengagement of the teeth of gear segment 17:: and rack portion 16, whenlatch 11 is in a half pulled-back position. Such location of bores 25gives a maximum travel of latch 11 for a minimum travel of lever arm 22along pin 19a, for a given position of pin 19a in a selected bore 25.

As shown in FIGS. 4 and 5, in order to reduce the size of the lock,sockets 7a are located within lock box 1. One of these sockets,designated as 712, acts as a stop to limit the movement of gear segment17a and thereby limit the withdrawal movements of latch 11 and bellcrank lever 20.

To further guide latch 11 in its movement, it is provided with anextension 11a slidable in a suitable opening formed in the wall of lockbox 1.

In the embodiment of FIG. 6, hairpin type spring 26 is pivoted aroundshaft 21, with one arm engaging the bottom of the lock box and the otherarm engaging lever arm 23 of hell crank 20 to move it in the latchwithdrawal direction. Movement in such direction is prevented by a trip27 engaging a nose portion on lever arm 22. Trip 27 may be in the formof a resilient member riveted to the bottom of the lock box, as shown inFIG. 6.

To unlock the closure, a push button 28 which overlies trip 27, or whichis otherwise connected to depress trip 27, is operated. Movement of pushbutton 28 actuates the trip out of engagement with lever arm 22 andpermits pivotal movement of bell crank lever 20 under the influence ofspring 26 to assume its position wherein it can be grasped and used as ahandle to fully withdraw the latch and to open the closure. The dottedlines in FIG. 6 show the positions of the movable elements in theirprojected position so that lever arm 23 may be grasped and operated. Itis apparent that in this embodiment, recess 24 may be eliminated.

Spring 26 may be made stronger than holding spring 12. In the event whenpush button 28 is actuated, spring 26 will move bell crank lever 20 toits final position wherein the latch is fully withdrawn and lever arm 23may serve as the closure handle.

FIGS. 7 and 8 show the details of safety and locking means designated as30 in FIG. 1. Means 30 comprises a member 31 fixed to the lock box 1. Alocking plug 32, carrying a locking finger 34, is mounted in a bore ofmember 31. Plug 32 has a key slot formed therein which may be of avaried shape so that only a key of a mating shape would fit therein.Plug 32 and its key slot 33 are merely a diagrammatic representation ofa locking device and may assume any form, such as a tumbler type lockingmeans or a plain key type. Member 31 houses a spring pressed detent 35which may interengage with either of recesses 36 or 37 formed in plug32, whereby the detent 35 maintains plug 32 in either of its twopositions.

FIG. 1 shows in solid lines plug 32 and its finger 34 in a positionwhich permits latch withdrawing movement of gear segment 17. If it isdesired to lock the closure, plug 32 is turned by means of a mating keyto bring finger 34 in the path of movement of gear segment 17 to therebyblock its movement. The blocking position of finger 34- is shown by thedotted lines in FIG. 1. Plug 32 and finger 34 are thereafter retained inblocking position by detent 35 engaging recess 37, and the closure willstay locked until plug 32 is returned to unlocked position.

While the forms of the invention herein described constitute preferredembodiments, it is to be understood that the invention is not limited tothe precise structures disclosed, and that changes may be made thereinwithout departing from the scope of the invention which is defined inthe following claims.

What is claimed is:

1. A spring lock comprising a thin, fiat lock casing with main walls andsmaller side walls adapted to be secured to the element to be locked, alatch slidable within said casing having a locking position wherein itsend protrudes from said casing, spring means biasing said latch to itslocking position, a unitary plate member to initially withdraw the latchand thereafter serve as a handle means, said plate member being in theform of a bell crank lever with a short lever arm and a relativelylonger lever arm and being pivotable about an axis which extendsperpendicularly to the sliding direction of the latch and parallel tosaidunitary plate member, said short lever arm extending within thecasing and the longer arm closely overlying a portion of said casingwhen said latch is in its locking position, means to support said platemember for pivotal movement, motion transmitting means directlyactivated by said short arm to transmit unlocking motion from saidmember to said latch, said motion transmitting means being pivotableabout an axis which extends perpendicularly to the sliding direction ofthe latch and also perpendicularly to the axis of the plate member, saidmotion transmitting means engaging the slidable latch at a side facingthe smaller side wall of the casing, a depression providing a fingerrecess struck in the wall of the casing adjacent the overlying longerlever arm to permit the insertion of a finger below said longer arm forapplying a pivoting force to the plate member to move it in a directionto cause an initial movement of the short lever arm and the motiontransmitting means in a direction to withdraw the latch against itsspring bias and thereafter bring the long lever arm into a positionwherein it is substantially angularly related to the casing to serve asa handle.

2. A spring lock in accordance with claim 1, wherein the motiontransmitting means comprise a pivoted gear segment oscillated bymovement of said short lever arm and a rack means interconnecting saidgear segment and latch.

3. A spring lock in accordance with claim 2, wherein said gear segmenthas a series of bores, the centers of which are located on a linepassing through the center of the gear segment pivot and the point ofengagement of the teeth of the gear segment with the teeth of the rackwhen the earth are in the position corresponding to a half unlockingmovement of the latch, and a pin insertable in a preselected bore, saidfirst lever arm abutting said pin to transmit movement to said gearsegment.

4. A spring lock in accordance with claim 1, said lock casing havingmeans for securing the lock casing to the desired element, said securingmeans being within the area defined by the overlying portion of the longlever arm.

5. A spring lock in accordance with claim 1, second spring means biasingsaid plate member in the latch withdrawal direction against said firstclaimed spring means, trip means to prevent movement of said platemember by said second spring means, and push button means operativelyconnected to said trip means to disable it and thereby permit movementof the plate member in the latch withdrawal direction.

6. A spring lock in accordance with claim 1, and locking means locatedadjacent the motion transmitting means to prevent movement thereof in alatch withdrawing direction.

7. A spring lock in accordance with claim 6, said locking meanscomprising a mounting means secured to said lock casing adjacent saidmotion transmitting means, and key operated means supported by saidmounting means and operable to a first position wherein it is in thepath of movement of the motion transmitting means to prevent movementthereof, and operable to a second position lying out of said path.

8. A spring lock in accordance with claim 7, wherein said key operatedmeans comprise a keyed plug rotatable 6 in said mounting, a membersecured to said plug to be moved thereby into and out of the path ofsaid motion transmitting means, and detent means for maintaining saidplug in either of its positions.

9. A spring lock in accordance with claim 1, wherein the lock casingincludes side walls, angular extensions on said side walls, and threadedsocket means secured to said extension for reception of fastening screwstherein.

References Cited UNITED STATES PATENTS 1,199,849 10/1916 Willoughby105-434 1,557,581 10/1925 Harrington 292173 X 2,075,948 4/1937 Kuszmaul292173 X 2,642,300 6/1953 Pelcin 292173 2,934,370 4/ 1960 Love 2921422,900,204 8/1959 Pelcin 292173 3,055,204 9/1962 Pelcin 153 3,159,41512/1964 Sandor 2923363 3,250,558 5/1966 McClintock 292229 1,964,0666/1934 Kuszmaul 292172 X 3,044,815 7/1962 Soss 292173 3,209,563 10/1965Pelcin 292173 X RICHARD E. MOORE, Primary Examiner E. J. MCCARTHY,Assistant Examiner US. Cl. X.R. 292172

